JP2021535941A - Epoxy composite formulation - Google Patents

Abstract

(A) at least one epoxy resin compound, (b) at least one curing agent, (c) at least one curing accelerator, (d) at least one internal mold release agent, and (e) at least one. An epoxy resin composition useful for making a molded composite article comprising a reaction inhibitor, and a molded composite article made from the above epoxy resin composition. [Selection diagram] None

Description

The present invention relates to epoxy composite formulations and composites made from such formulations suitable for use in automotive applications.

Carbon fiber epoxy composites can be used in many applications, including automotive parts. For automotive applications, it achieves (1) compression molding and curing in less than 5 minutes (minutes), (2) maintaining a high glass transition temperature (Tg), and (3) high strength and high stiffness properties. It is necessary to make a carbon fiber epoxy composite with continuous alignment or cutting random fibers that can be. However, known epoxy composite formulations tend to adhere to steel and aluminum mold surfaces. Previously, external mold release agents have been used to aid in the release of the cured complex from the mold. However, the use of external mold release agents tends to slow down the formation time, inconsistent application between parts, and ineffective when the composite formulation flows and fills the mold. Therefore, there is a need for an internal mold release agent (IMR) agent for the epoxy composite formulation to avoid the aforementioned problems when using an external mold release agent.

There are several IMRs on the market. For polyester type composites, the most commonly used IMR is zinc stearate. For epoxy composites, there are some unique compositions sold for use in epoxy systems, and there are different products recommended based on curing chemistry and related molding conditions. Internal release materials available from Axel Plastics Laboratories can be found at "http://axelplastics.com/node/26". However, known recommended solutions using IMR do not work with dicyandiamide-cured epoxy resin systems under certain desired process conditions.

U.S. Pat. No. 5,906,784 discloses a curable epoxy resin and discloses the use of a wax having a drop point of 80 ° C. to 90 ° C. Waxes are used as IMR agents in epoxy formulations that cure with polycarboxylic acids or anhydrides. In the teachings of the above patent, the wax is described as a montan ester. The Licowax KSL available from Clariant meets all of the properties of Montan wax listed in the above patent. However, when Licowax KSL is used in a dicyandiamide cured epoxy system, the cured portion is not released from the mold. Further, the above patent teaches after curing at 160 ° C. for 10 minutes, followed by curing at 135 ° C. for 2 hours (hours). This curing time is not very efficient.

U.S. Pat. No. 5,919,843 discloses a halogen-free, flame-retardant epoxy resin molding compound. The above patent discloses the use of Montan wax as one of several possible IMR agents for phenolic curable epoxy resin molding compounds for encapsulating electronic elements. The above patent does not specify the type of montan ester to be used. However, most montane esters do not work with epoxy resin systems, especially dicyandiamide-cured epoxy composite formulations systems.

Thus, in view of the ongoing need to find solutions to the prior art problems associated with the use of IMR agents, for example, (1) being easily incorporated into epoxy formulations during molding. To produce a molded composite that contains an IMR agent that does not require an additional application step and can be easily released from the mold during molding at high temperatures (eg, (>) above 145 ° C.). Provided are epoxy resin composite formulations that can (3) produce a molded composite with a curing cycle time of less than 5 minutes and (4) be cured with a dicyandiamide (abbreviated as "disy" herein) curing agent. (5) It is desirable to provide a beneficial epoxy composite formulation that cures to form a composite part, which, when contained an IMR agent, does not reduce the Tg of the cured portion by more than 10% (%). Will. Epoxy composite formulations that meet the above requirements are highly desirable.

The present invention relates to epoxy composite formulations that meet all of the above materials and process requirements for producing epoxy-carbon fiber composites. Advantageously, the epoxy composite formulations of the present invention achieve good release performance in a dicy-cured epoxy resin system, for example when cured at temperatures above 145 ° C., the epoxy composite formulations of the present invention. Achieve full curing properties in less than 5 minutes.

In one embodiment, the invention comprises (a) at least one epoxy resin compound, (b) at least one curing agent for curing the epoxy reaction, and (c) at least one for curing the epoxy reaction. It relates to a curable epoxy composite formulation or composition comprising an accelerator, (d) at least one internal demolding agent, and (e) at least one reaction inhibitor. It is possible to provide a curable molded composite article in which the curable epoxy composite composition can be cured and easily released from a molding tool.

In another embodiment, the invention relates to a curable epoxy-based resin composite composition comprising (A) the curable epoxy composite composition described above and (B) at least one structural material. In a preferred embodiment, the curable epoxy based resin composite composition can be a dyssy curable epoxy resin composite composition and the at least one structural material can be a fiber.

In yet another embodiment, the invention includes the above epoxy resin composite compositions and methods of making the composites.

It is a graph which illustrates the plot of the heat flow vs. time of various composite resin formulations.

In one broad embodiment, the novel epoxy composite composition or formulation of the invention comprises (a) at least one epoxy resin compound, (b) at least one curing agent for curing the epoxy reaction, and (c). ) Includes at least one accelerator for curing the epoxy reaction, (d) at least one internal release agent, and (e) at least one reaction inhibitor. The epoxy composite composition according to the present invention can be used to form a molded composite article having a structural material such as a fiber material.

The curable resin composition of the present invention contains at least one epoxy resin. Epoxy resins or mixtures (if two or more different resins are present) are generally the major constituents of curable resin compositions. Epoxy resins useful for preparing composite compositions may include liquid epoxy resins, epoxy novolac resins, solid epoxy resins, and mixtures thereof. In one preferred embodiment, the epoxy resin or mixture thereof can itself be a non-adhesive solid at 23 ° C. In another preferred embodiment, the epoxy resin or mixture thereof can be thermally softened by itself at temperatures of 40 ° C to 80 ° C, and in another embodiment of 40 ° C to 65 ° C. Still in another embodiment, the epoxy resin may comprise at least one epoxy resin that is solid at 23 ° C., and in yet another embodiment, the epoxy resin composition is one or more solid at 23 ° C. It may contain a mixture of the epoxy resin and one or more epoxy resins that are liquid at 23 ° C.

The epoxy resin or mixture thereof is, for example, at least 210 grams / equivalent (g / equivalent) or at least 220 g / equivalent, up to 1,000 g / equivalent in one embodiment, up to 500 g / equivalent in another embodiment, and yet another. In embodiments, it may have up to 350 g / equivalent, or in yet another embodiment up to 300 g / equivalent of epoxy equivalent (EEW).

The epoxy resin or mixture thereof is, for example, at least 2.4 epoxy groups per molecule in one embodiment, at least 2.5 epoxy groups per molecule in another embodiment, or at least 2.6 per molecule in another embodiment. It may have a number average epoxy functional group of epoxy groups. Further, the number average epoxy functional group is, for example, up to 6 epoxy groups per molecule in one embodiment, up to 4 epoxy groups per molecule in another embodiment, and up to 3.5 epoxy groups per molecule in another embodiment. Or in yet another embodiment, it can be up to 3.0 epoxy groups per molecule.

A wide range of epoxy resins may be suitable for the epoxy resin contained in the epoxy resin composite composition. In one preferred embodiment, the epoxy resin useful in the present invention may contain at least one polyglycidyl ether of polyphenols. Examples of polyphenol polyglycidyl ethers include (i) resorcinol, catechol, hydroquinone, biphenol, bisphenol A, bisphenol AP (1,1-bis (4-hydroxylphenyl) -1-phenylethane), bisphenol F, and bisphenol K. , Bisphenol M, and diglycidyl ethers of polyvalent phenolic compounds such as tetramethylbiphenol, (ii) C2-24 alkylene glycols and aliphatic glycols and polys such as poly (ethylene oxide) or poly (propylene oxide) glycol diglycidyl ethers. Diglycidyl ether of ether glycol, polyglycidyl ether of alkyl substituted phenol-formaldehyde resin such as (iii) phenol-formaldehyde novolak resin (epoxynovolac resin), epoxy cresol novolak resin, phenol-hydroxybenzaldehyde resin, and cresol-hydroxybenzaldehyde resin. (Each has three or more epoxy groups per molecule), (iv) may include, for example, oxazolidone group-containing polyglycidyl ethers of phenolic compounds as described in US Pat. No. 5,112,932. .. Such epoxy resins include diisocyanates such as diphenylmethane diisocyanate or toluene diisocyanate, resorcinol, catechol, hydroquinone, biphenol, bisphenol A, bisphenol AP (1,1-bis (4-hydroxylphenyl) 1-phenylethane), bisphenol. Includes reaction products of diphenols such as F, bisphenol K, and tetramethylbiphenol with diglycidyl ethers. These epoxy resins are, for example, 1.9 to 2.5 in one embodiment, 1.9 to 2.2 in another embodiment, and, for example, 300 to 500 in another embodiment. In the embodiment of 325-450 epoxy equivalents, (v) dicyclopentadiene-phenolic resin and dicyclopentadiene-substituted phenolic resin, (vi) any of the above types (i), (ii), or (iii). It may have any combination of two or more of the partially advanced epoxies, as well as the epoxies on (vii).

Many of the above epoxy resins of types (i) to (vi) are commercially available. Moreover, some of the commercially available epoxy resin products can often be a blend of two or more of the above epoxy resins. For example, commercially available polyglycidyl ethers of bisphenol A and bisphenol F that may be useful in the present invention include D.I. E. R. (Registered Trademark) 330, D.I. E. R. (Registered Trademark) 331, D.I. E. R. (Registered Trademark) 332, D.I. E. R. (Registered Trademark) 354, D.I. E. R. (Registered Trademark) 383, D.I. E. R. 661, and D.I. E. R. (Registered Trademark) 662 Resins sold by Olin Corporation are included. Generally, such epoxy resins have more than two epoxy functional groups.

Commercially available diglycidyl ethers of polyglycols include D.I., available from Olin Corporation. E. R. (Registered Trademarks) 732 and D.I. E. R. (Registered Trademark) 736 may be included.

In other embodiments, commercially available epoxy novolac resins that may be useful in the present invention include, for example, D.I. E. N. (Registered Trademark) 354, D.I. E. N. (Registered Trademark) 431, D.I. E. N. (Registered Trademark) 438, and D.I. E. N. (Registered Trademark) 439 may be included. In general, these epoxy novolak resin products can have, for example, an epoxy equivalent of 150-200 in one embodiment, for example 2.2-5.0 in one embodiment and 2.6-in another embodiment. It may have an epoxy functional group of 4.0.

Other embodiments that may be useful in the present invention are Huntsman Araldite ECN1273, Epon® 164 and Epon® 165 from Hexion, and Epicron N-660, Epicron N-664, Epiclin from DIC Americas. Commercially available epoxy cresol novolak resins such as N-670, Epicron N-673, Epicron N-680, Epicron N-690, and Epicron N-695 may be included. In general, these epoxy cresol novolak resin products can have, for example, 180-250 epoxy equivalents in one embodiment, eg 2.2-5.0 in one embodiment and 2. in another embodiment. It may have 6-4.8 epoxy functional groups.

Suitable commercially available epoxy resins containing an oxazolidone group and may be useful in the present invention include D.I. E. R. 6508 (available from Olin Corporation) may be included.

In one embodiment of the invention, the epoxy resin useful in the epoxy resin composition of the present invention may include a liquid epoxy resin in combination with an epoxy novolak resin. For example, the epoxy resin composition may contain a liquid epoxy resin, which is a diglycidyl ether of bisphenol A, and an epoxy novolak resin, which is a polyglycidyl ether of phenol-formaldehyde novolac. In one embodiment, based on the total weight of all the epoxy resins in the epoxy resin composition, the diglycidyl ether of the bisphenol A epoxy resin is in the composition in an amount of 0% by weight (% by weight) to 65% by weight. The epoxy novolak resin may be present in the composition in an amount of 0% to 70% by weight. In one preferred embodiment, based on the total weight of all epoxy resins in the epoxy resin composition, the diglycidyl ether resin may be present in the composition in an amount of 10% to 40% by weight, epoxy. The novolak resin may be present in the composition in an amount of 15% by weight to 62% by weight. In another preferred embodiment, the diglycidyl ether liquid epoxy resin may be present in the composition in an amount of 15% to 30% by weight, based on the total weight of all the epoxy resins in the epoxy resin composition. The epoxy novolak resin may be present in the composition in an amount of 25% to 46% by weight.

In another embodiment, when the epoxy component in the composition is only a liquid epoxy resin, the liquid epoxy resin present in the epoxy resin composition is based on the total weight of the components in the epoxy resin composition. The amount may range from 35% to 90% by weight in one embodiment, 45% to 85% by weight in another embodiment, and still 55% to 75% by weight in another embodiment.

In yet another embodiment, if the epoxy component in the composition is only a solid epoxy resin, a solid useful in the epoxy resin composition based on the total weight of all the epoxy resins in the epoxy resin composition. The amount of epoxy resin can range from 10% to 65% by weight, in another embodiment from 15% to 55% by weight, and even further in another embodiment from 20% to 45% by weight. In one preferred embodiment, the amount of solid epoxy resin in the epoxy resin composition can be 25% to 43% by weight based on the total weight of the constituents in the epoxy resin composition.

In yet another embodiment, if the epoxy constituents in the curable resin composition contain a mixture of any of the above types of epoxy resins (a)-(f), such epoxy resins are combined. It may constitute at least 50% by weight, at least 75% by weight, at least 90% by weight, or at least 95% by weight of the total weight of all the epoxy resins present in the curable resin composition. Alternatively, the combination of epoxies used in the composition may make up 100% of the total weight of all epoxies.

In yet another embodiment, the curable resin composition comprises (1) at least one diglycidyl ether of bisphenol product, (2) at least one epoxynovolac resin product, and (3) at least one oxazolidone. It may contain a combination of epoxy resin products contained, and these three products together may be 90% to 100% by weight or 95% by weight of the total weight of all epoxy resins present in the curable resin composition. Consists of% to 100% by weight.

In some embodiments, other epoxies may be present in the composition, but in such embodiments, the other epoxies are present in small amounts, if any. Among these other epoxy resins are alicyclic epoxides, including those described in US Pat. No. 3,686,359. These alicyclic epoxides include, for example, (3,4-epoxycyclohexyl-methyl) -3,4-epoxy-cyclohexanecarboxylate, bis- (3,4-epoxycyclohexyl) adipate, vinylcyclohexene monooxide, and A mixture thereof may be included.

In other embodiments, the epoxy resin that can be used in the composition is not necessarily rubber modified and does not necessarily contain a polyether group. However, rubber modification and modification with a reinforcing agent containing an epoxy-terminated polyether and / or a polyether having a capped terminal isocyanate group is within the scope of the present invention.

The curable resin composition contains at least one curing agent for curing the epoxy resin. In one preferred embodiment, the curing agent is a latent type having an activation temperature of at least 100 ° C., and in another embodiment at least 120 ° C. The curing agent cures (crosslinks) the epoxy resin when heated to a temperature of at least 100 ° C., but does not cure the resin at room temperature (about 22 ° C.) or at a temperature of up to at least 50 ° C. (or the resin is very cured). (Slow), so it is latent. The curing agent has a high melting temperature (eg, greater than 200 ° C.) due to, for example, blocked reactive groups, encapsulation, and / or until exposed to high temperatures (eg, greater than 150 ° C.). It can be latent due to its limited solubility in epoxy resins (or mixtures).

The activation temperature of the curing agent is a combination of the curing agent and a diglycidyl ether of bisphenol A having an epoxy equivalent of 182 to 192 in a chemical ratio, and the combination is applied between the two substrates at various temperatures. Can be assessed by heating in 2 hours and then in each case measuring the lap shear strength according to DIN ISO 1465. Another sample can be cured at 180 ° C. for 30 minutes, which condition represents a "complete cure" condition. "Activation temperature" refers to the minimum cure temperature at which the combination achieves at least 30% lap shear strength obtained under "complete cure" conditions.

Suitable latent curing agents useful in the compositions of the present invention include, for example, boron trichloride / amine and boron trifluoride / amine complexes; melamine; diallyl melamine; 3-amino-1,2,4-triazole and the like. Aminotriazole; dicyandiamide; methylguanidine, dimethylguanidine, trimethylguanidine, tetramethylguanidine, methylisoviguanidine, dimethylisoviguanidine, tetramethylisbigandidine, heptamethylisoviguanidine, hexamethylisoviguanidine, acetoguanamine, and Guanidines such as benzoguanamine, as well as mixtures thereof, may be included. Other examples of suitable latent hardeners that can be used in embodiments of the invention are hydrazides such as adipic acid dihydrazide, dihydrazide stearate, dihydrazide isophthalic acid, and dihydrazide terephthalate; semicarbazide; cyanoacetamide; diaminodiphenyl sulfone. Aromatic polyamines such as; as well as mixtures thereof may be included. In one embodiment, for example, a mixture of guanamine and dihydrazide can be used. The use of dicyandiamide, isophthalic acid dihydrazide, adipic acid dihydrazide, and 4,4'-diaminodiphenyl sulfone can be used in one preferred embodiment. In yet another preferred embodiment, the curing agent can be dicyandiamide. Suitable dicyandiamide latent curing agents that can be used in embodiments of the present invention are AC Catalysts Inc. It is available from the product name Technology Nanody.

In a preferred embodiment, the curing agent is a micronized latent curing agent such as dicyandiamide. Typically, the micronized latent hardener has a maximum particle diameter of 98% of the particles less than 10 microns (μ) and at least 35% of the particles have a particle diameter of less than 2μ. It has a distribution and provides a faster curing rate of the epoxy resin composition. Fast curing rates are particularly desirable for molded articles and automated applications where high throughput is required in the production of articles.

In one preferred embodiment, the latent curing agent has a maximum particle diameter of 98% of the particles less than 6μ and in another embodiment 98% of the particles have a maximum particle diameter of 4μ or less. Has a size distribution. In yet another embodiment, at least 45% of the particles have a diameter of less than 2μ, and in yet another embodiment, at least 55% of the particles have a diameter of less than 2μ, yet another embodiment. In, at least 90% of the particles have a diameter of less than 2μ. In a preferred embodiment, 100% of the particles have a diameter of less than 2μ. Particle size can be measured with a laser diffraction system such as the Beckman Colter LS13-320 Laser Diffraction Particle Size Analyzer equipped with a tornado dry powder system.

The latent curing agent in the epoxy resin composition is present in an amount sufficient to cure the epoxy resin. In one general embodiment, the latent curing agent is in sufficient quantity to provide at least 0.75 epoxy reactive groups per epoxide group provided by the epoxy resin (or mixture thereof). It can exist in things. The amount is at least 0.85 epoxide-reactive groups per epoxide group in another embodiment, still at least 0.90 epoxide-reactive groups per epoxide group in another embodiment, or epoxide in yet another embodiment. It can be at least 0.95 epoxy reactive groups per group. In other embodiments, the curing agent is an epoxy reactive group up to 1.5 per epoxy group, an epoxy reactive group up to 1.25 per epoxy group, an epoxy reactive group up to 1.15 per epoxy group, an epoxy. It may provide up to 1.10 epoxy reactive groups per group, up to 1.05 epoxy reactive groups per epoxy group, or up to 1.02 epoxy reactive groups per epoxy group.

In one embodiment, the latent curing agent is present in an amount relative to the total amount of epoxy resin in the composition. The amount of latent curing agent in the epoxy resin composition is typically 5% to 15% by weight, more typically about 6% to 12% by weight, based on the total weight of the epoxy resin composition. Is. In a preferred embodiment, the amount of latent curing agent in the epoxy resin composition can be 7% to 8% by weight based on the total weight of the epoxy resin composition.

The curable resin composition comprises at least one accelerator for the reaction of the epoxy resin in the presence of a curing agent (such as dyssy). The accelerator (or cure catalyst) can also be a latent type accelerator that can be encapsulated (or blocked) or otherwise activated only when exposed to high temperatures (eg, above 100 ° C.). .. The latency of the catalyst can be directly due to the chemical structure of the catalyst. For example, the actual catalytically active species of the blocked latent catalyst is generally not present until it is produced by the aforementioned high temperature unblocking reaction typically used during the molding process. Accelerator additives or latent catalysts can also be soluble in the epoxy resin of the curable composite composition, so that when solubilized, the solubilized catalyst is heated to the aforementioned high temperatures. Can hide.

As used herein, the term "soluble" with respect to a latent catalyst means that the catalyst is an epoxy resin prior to injecting the epoxy resin composition into structural materials such as the fibrous materials described below herein. It needs to be substantially soluble in the composition. In one embodiment of the specification, "substantially dissolved" means that more than 90% of the catalyst is dissolved in the epoxy resin composition and in another embodiment more than 95% of the catalyst is dissolved in the epoxy resin composition. Yet another embodiment means that 100% of the catalyst is dissolved in the epoxy resin composition. Typically, it is desirable to dissolve the catalyst in the epoxy resin composition during mixing of the epoxy resin composition.

Examples of accelerators that can be used in embodiments of the invention may include urea, substituted urea, modified imidazoles, and mixtures thereof. For example, urea useful in the compositions of the present invention includes toluenebis-dimethylurea; p-chlorophenyl-N, N-dimethylurea; 3-phenyl-1,1-dimethylurea; 3,4-dichlorophenyl-N, N-dimethylurea; N- (3-chloro-4-methylphenyl) -N', N'-dimethylurea; various aliphatic urea compounds such as the urea compound described in EP1 916 272, and mixtures thereof. Can be included. Other suitable latent catalysts useful in the present invention include, for example, tert-acrylic or alkyleneamines such as benzyldimethylamine; 2,4,6-tris (dimethylaminomethyl) -phenol; piperidin or derivatives thereof; 2 , 4-Diamino-6- [2'-methylimidazolyl- (1')]-ethyl-s-triazine, 2,4-diamino-6- [2'-methylimidazolyl- (1')]-ethyl-s -Triazine isocyanuric acid adduct dehydrated; C _1- C ₁₂ alkylene imidazole or N-aryl imidazole, eg 2-phenyl-imidazole, 2-methyl imidazole, 1-methyl imidazole, 2-ethyl-4-methyl imidazole, 4 , 4'-Methylene-bis (2-ethyl-5-methylimidazole) 2-ethyl-2-methylimidazole, or N-butylimidazole and 6-caprolactam; incorporated into a poly (p-vinylphenol) matrix 2, For novolak resins, including 4,6-tris (dimethylaminomethyl) phenols (as described in European Patent EP0 197 892); or the resins described in US Pat. No. 4,701,378. Incorporated 2,4,6-tris (dimethylaminomethyl) phenol, as well as mixtures thereof, may be included.

In one preferred embodiment, the soluble latent catalyst useful in the present invention may be the blocked urea catalyst described above, which is latent and soluble in epoxy resin. An example of a suitable latent urea catalyst that may be used in embodiments of the epoxy resin composite composition of the present invention may be toluenebis-dimethylurea (“TBDMU”).

The latent catalyst used in the epoxy resin composition should be present in the epoxy resin composition in a catalytically effective amount. Such a suitable catalyst effective amount is, for example, 0.1 parts by weight (PHR) to 10 parts by weight (PHR) per 100 parts by weight of the epoxy resin (s) in one general embodiment, and 0. It can be 25 PHR to 5 PHR, and still 1 PHR to 5 PHR in another embodiment.

The curable resin composition also contains at least one internal mold release (IMR) agent as the constituent (d). The IMR agent is a substance contained in a mold of a cured composition or a curable resin composition that reduces adhesion of the curable resin composition to other cured surfaces. Examples of IMR agents include fatty acids having 16 or more carbon atoms in one embodiment and 18 to 36 carbon atoms in another embodiment. Also useful in the present invention may be IMR agents such as alkali metals or ammonium salts, monoalkyl esters, monoalkyl amides, and diglycerides and / or triglycerides of such fatty acids, and mixtures thereof. A useful type of internal release includes a mixture of fatty acids with 18 to 36 carbon atoms and diglycerides and / or triglycerides with fatty acids with 10 to 36 carbon atoms. In one preferred embodiment, the IMR agent may include a montanic acid ester of triglycerol, such as Licorub WE4, available from Clariant.

The IMR agent may be present in the curable resin composition in an amount effective to reduce the adhesion of the cured composition to the mold or other surface. Suitable amounts of the IMR agent present in the curable composition are, for example, at least 0.5 parts by weight (PHR) per 100 parts by weight of the epoxy resin (s) in one embodiment and at least 1 PHR in another embodiment. It can be at least 1.5 PHR to up to 10 PHR in yet another embodiment, up to 7 PHR in yet another embodiment, up to 5 PHR in yet another embodiment, or up to 4 PHR in yet another embodiment.

The composite formulation of the present invention also comprises at least one reaction inhibitor compound as a constituent (e). For example, the reaction inhibitor, component (e), may contain hydrocarbons having carbon atoms above C18 and acid functional groups. The acid functional group can be, for example, a carboxylic acid or a derivative thereof, a sulfonic acid or a derivative thereof, maleic anhydride or a derivative thereof, and a mixture thereof. Reaction inhibitors include, for example, hydrocarbons with acid functional groups (greater than C18), such as montan fatty acids, erucic acid, United ™ acid available from Baker Hughes, CERAMER ™ available from Baker Hughes. , And sulfonates, such as E-Space 100 available from Ethox Chemicals LLC.

The amount of reaction inhibitor present in the epoxy composite composition is at least 0.5 parts by weight (PHR) per 100 parts by weight of the epoxy resin (s) in one embodiment, at least 1 PHR in another embodiment, and still different. Can be at least 1.5 PHR to up to 10 PHR in one embodiment, up to 7 PHR in yet another embodiment, up to 5 PHR in yet another embodiment, or up to 3 PHR in yet another embodiment.

The curable epoxy resin composition may contain various other components, compounds, or additives as component (f). Any additives that can be added to the curable resin formulations of the present invention include, for example, one or more diluents, enhancers, rubbers, plasticizers, bulking agents, colorants, flame retardants, smoke suppressants, thixotropy. Agents, adhesion promoters, repellents, antioxidants, other co-catalysts, other accelerators, surfactants, flow modifiers, stabilizers, and mixtures thereof may be included. Curable resin compositions also include calcium carbonate, fumed silica, and / or carbon nanotubes that fill the gaps between fibers on or near the surface of the molded compound and the cured composite to provide a smoother surface. It may contain finely divided solids. Typical epoxy resin compositions may also contain some fillers or other functional chemicals for any intended use.

In one broad embodiment, the methods for producing an epoxy composition useful for making a complex are: (a) at least one epoxy resin compound, (b) at least one curing agent, and (c). ) Includes mixing at least one accelerator, (d) at least one internal release agent, and (e) at least one reaction inhibitor.

In one embodiment, and as one non-limiting example of the invention, the epoxy resin composite composition is 80% to 90% by weight based on the weight of all the constituents in the composition. , 6% to 8% by weight curing agent, 2% to 5% by weight accelerator, 2% to 5% by weight IMR agent, 2% to 5% by weight reaction inhibitor, May include. Once the epoxy resin composition is formed, the composition can be combined with structural materials such as carbon fibers to produce composite articles.

The components on the epoxy composite composition can be mixed together in a conventional mixing device and under conventional mixing conditions known in the art. If desired, one or more additional arbitrary compounds may be added to the resin formulation.

In general, the mixing of the above components (a) to (e) constituting the curable resin composition is 60 ° C. to 90 ° C. in one embodiment, 65 ° C. to 85 ° C. in another embodiment, and still another. In the embodiment, it can be carried out at a temperature of 70 ° C to 80 ° C. When the constituents (a) to (e) are completely mixed to form the curable resin composition, the curable composition is ready to be cured, and the fibers or other structures are prepared before the composition is cured. The material can be added to the curable resin composition to form an epoxy-based resin composite composition, which can be cured to form the composite articles described below herein.

The curable epoxy resin composite composition of the present invention has some beneficial properties and performances, especially when suitable components are mixed with each other to form a dyssy curable epoxy resin composition. For example, some advantages of using the curable epoxy resin compositions of the present invention include: (1) Compounds constituting curable compositions such as IMR agents and reaction inhibitors. Does not require the use of additional application steps during the molding process as it can be easily incorporated into epoxy resin formulations; (2) constitutes components of curable compositions such as IMR agents and reaction inhibitors. The compound can help release the molding composite from the molding tool during molding at high temperatures (eg, (>)> 145 ° C; (3) curable composition such as IMR agents and reaction inhibitors. The compounds that make up the constituents of the product can help release the molded composite in a cure cycle time of less than 5 minutes; (4) make up the constituents of the curable composition such as IMR agents and reaction inhibitors. The constituent compounds can help release the dyssy-cured epoxy resin from the mold that cures in less than 5 minutes; and (5) the compounds that make up the constituents of curable compositions such as IMR agents and reaction inhibitors. Does not reduce the Tg of the cured composite part by more than 10%. Further, the epoxy composite article of the present invention can be achieved by blending the epoxy composite compound of the present invention with a dyssy curing agent and curing by isothermal molding at a temperature of more than 140 ° C.

Epoxy composite formulations of the present invention, suitable and beneficial induction time indicates the t _i. Induction time t _i of the composition, using a differential scanning calorimetry can be measured using a isothermal method at a molding temperature of the composition. Composite part after molding is molded at 0.99 ° C., _(measured at 0.99 ° C.) t i is the time more than 15 seconds, it is normally released from the mold tool. The induction time of the composition of the present invention can be controlled by the amount of the IMR agent and the reaction inhibitor added to the composition. The components in the composition are that the IMR agent rises on the surface of the epoxy resin formulation and (2) rests at the interface between the surface of the formulation and the surface of the metal surface of the mold. And (3) the IMR agent is allowed to function normally (for its intended use as an internal mold release agent) and after the composition has undergone a curing time of less than 5 minutes, the final curing product is molded. It is necessary to provide sufficient induction time long enough to allow release from (without any part of the curing product adhering to the mold).

Molded articles made from blends of the present invention having an induction time t _i of more than 15 seconds, at isothermal molding temperature of the composition is 145 ° C. to 160 ° C., it is molded of (<) of less than 5 minutes cure time If, and in particular, if the formulation is cured with a dyssy hardener, it provides for the successful release of the part from the mold. If the molding temperature is less than 145 ° C, the curing time increases and the glass transition temperature of the cured portion decreases, so it is not desirable to reduce the molding temperature to less than 145 ° C.

One of the objects of the present invention is that when the composition is cured to form a cured portion or article in a mold, 15 seconds is required so that the cured portion is normally released from the mold. To provide a curable composition that exhibits an induction time greater than that, the IMR agent is raised onto the surface of the composition. It has been found that using the curable formulations of the present invention, for example, one or more of the following methods can achieve an induction time of greater than 15 seconds for the formulation: (1). Use the appropriate ingredients in the formulation, (2) use the appropriate residence time to blend the ingredients, eg, at a blending temperature of> 60 ° C., and / or (3) the appropriate cure (molding). Use process steps and conditions.

(1) Formulation In the component of the formulation of the present invention, that is, the dyssy-cured epoxy composite composition, when the present composition is cured, the obtained cured portion is remarkably adhered to the surface of the mold tool and cured. Ensure that at least one IMR agent and at least one reaction inhibitor are present in the composition so that they can be successfully released from the mold tool without compromising the integrity of the portion. Can be changed as Embodiments of IMR agents and reaction inhibitors are described above herein.

The induction time of the formulation with the appropriate IMR agent and reaction inhibitor can be controlled, for example, by controlling the concentration of the IMR agent and / or the reaction inhibitor present in the formulation. It was found that as the concentration of the IMR agent increased, so did the induction time. However, it was also found that the Tg of the final cured compound decreased with increasing concentration of the IMR agent. INDUSTRIAL APPLICABILITY According to the present invention, the balance between controlling the concentration of the composition component and maximizing Tg was advantageously determined.

(2) Blending process The resin compound blend residence time in a batch process or a continuous process can be changed so as to maximize the induction time of the resin compound. In general, it has been found that the induction time of the resin formulation can decrease with increasing exposure time (retention blend time) of the resin formulation at temperatures above 60 ° C. Also, since the induction time of a particular composition may depend on the components of the prepared formulation, the exposure time and temperature of such composition may be varied to produce a composition with optimal properties. Can be provided.

As an example of the present invention, for example, in one embodiment, in a batch process, when the exposure time exceeds 6 hours at 80 ° C., the induction time is reduced to 0 and the molding adheres to the surface of the molding tool. Goods are brought. In another embodiment, for example in a continuous process, the epoxy resin formulation is blended with the appropriate curing agents, accelerators, IMR agents, and reaction inhibitors (and any other additives, if any) as described above. By doing so, such blends may provide a resin formulation capable of retaining an induction time of> 15 seconds.

It was also found that the induction time of the resin formulation decreased with increasing handling process conditions of the resin formulation. Twisting at high temperatures to achieve sufficient resin injection into structural materials such as fiber tow during the complex preparation process, for example when using prepreg injection, direct long fiber technology, and / or sheet molding formulations. Long injection times are recommended. However, it was found that longer injection times at elevated temperatures could reduce the induction time of the final complex.

(3) Curing / Molding Process It has also been found that the induction time of the resin formulation decreases with increasing process temperature and process time during the curing and molding process of the formulation to form the complex. For example, with respect to molding temperature, increasing the concentration of the IMR agent allows molding of the resin formulation at higher temperatures (eg> 145 ° C.).

As described above, the composite article or molded product of the present invention is made by mixing (A) the above epoxy composite composition with (B) at least one structural material additive, and then the above constituent (A). It can be produced by first preparing a cured formulation by curing the mixture of (B) and (B). In one preferred embodiment, the composite article is (A) a reaction product of the epoxy composite composition described above with (B) at least one fibrous material as a structural material additive.

Curable epoxy resin compositions or formulations have been described above. Generally, the amount of the curable resin composition, the component (A) used in combination with the structural material (for example, carbon fiber), and the component (B) for preparing a formulation for curing into a composite is. , A minimum of 80:20 to a maximum of 20:80 in one embodiment, and a resin composition vs. structural material of 50:50 to 60:40 in another embodiment (ie, component (A): component (B)). Can be used in the ratio of. In one preferred embodiment, the component (A): (B) ratio can be 40:60.

The structural material additive, component (B) used in the curable resin composition can be, for example, a non-metal substrate, particles, fibers, fillers, and other structural additives, as well as mixtures thereof.

In one preferred embodiment, the structural material, component (B) can be fiber or fibrous material. The fibers may be composed of a material that is chemically and thermally stable at the temperature of the forming and curing steps to form the final composite. Fibers useful in the present invention may include, for example, carbon fibers, graphite fibers, glass fibers, ceramic fibers, mineral fibers such as mineral wool, metal fibers, polymer fibers and the like, and mixtures thereof. In one preferred embodiment, the fibers may include carbon fibers, glass fibers, and mixtures thereof. In another preferred embodiment, carbon fiber can be used, for example, to make vehicles and / or aerospace composites. Still in another preferred embodiment, the fibrous structural material, constituent (B) useful in the composition may be a glass sphere.

The fibers may have a diameter of, for example, 250 nanometers (nm) to 500 μm in one general embodiment, 500 nm to 50 μm in another embodiment, and still 1 μm to 10 μm in another embodiment.

The fibers can be continuous fibers. The continuous fibers may be, for example, unidirectional, woven, knitted, braided, or mechanically entangled. Alternatively, the fibers can be cut, for example, the short fibers have a length of up to 100 mm (mm) in one embodiment and 3 mm to 50 mm in another embodiment. The cut fibers can be held together with the binder to form a fiber mat. In certain embodiments, the fiber can be a randomly oriented cut fiber having a length of 12 mm to 25 mm.

In general, the fiber content of a composite composition is, for example, 5% to 80% by weight of the total weight of the composition in one embodiment, 20% to 80% by weight in another embodiment, and yet another embodiment. In the form, it can be 35% by weight to 70% by weight. In one preferred embodiment, the fiber content of the composite composition can be, for example, 60% by weight.

Any compound, additive, or material can be added to the curable resin formulation of the invention to prepare a formulation for curing into a composite article. Any compound that can be used to form a composite article may be, for example, one or more impact resistant improvers, reactive diluents, coalescing agents, pigments, dyes, particles that may be routinely selected by one of ordinary skill in the art. It may include fillers, bulking agents, tackifiers, antioxidants, and wetting agents.

When used to form a composite, the amount of any compound, additive, or material present in the curable resin composition is generally 0% to 10% by weight in one embodiment, and another. In the embodiment of the above, it may be in the range of 1% by weight to 5% by weight.

To prepare the composite article, the curable resin composition described above is prepared, and then the additive may be added to the resin composition before the resin composition is cured. For example, in one embodiment, a fiber such as carbon fiber, glass fiber, or a mixture thereof is added to the resin composition, and then the mixture is cured to contain a molded composite article containing a cured molded resin containing the fiber. Can be formed.

In one embodiment, the methods for producing the composite article are (I) (a) at least one epoxy resin compound, (b) a dyssy hardener, (c) at least one accelerator, and (d). The step of mixing at least one internal demolding agent, (e) at least one reaction inhibitor, and (f) any other desired additive (s) for forming an epoxy composite formulation. And (II) a step of mixing a structural additive such as a fiber with the epoxy composite compound of step (I) to form an epoxy / fiber composite composition, and (III) an epoxy / fiber composite of step (II). Includes a step of curing the compound at an isothermal molding temperature (eg, a temperature above 145 ° C.).

When the constituents (a) to (e) are completely mixed to form a curable resin composition, the curable composition is heated above 140 ° C. in one embodiment, above 145 ° C. in another embodiment, and still. In another embodiment it can be cured at an isothermal molding temperature above 150 ° C. and yet in another embodiment above 160 ° C. Other embodiments of the curing temperature can be, for example, 140 ° C to 170 ° C and 145 ° C to 160 ° C.

The curing time of the dyssy curable epoxy resin composition is 120 seconds (seconds) to 5 minutes (minutes) in one embodiment, 120 seconds to 4 minutes in another embodiment, and 120 seconds to 2 in another embodiment. Can be minutes.

The composite articles of the present invention have some beneficial thermal and / or mechanical performance and properties. For example, the composite may have a high glass transition temperature (Tg) of> 140 ° C. in one embodiment, 140 ° C. to 170 ° C. in another embodiment, and still 150 ° C. to 170 ° C. in another embodiment. .. The Tg of the complex can be measured by the method described in ASTM D5418-15. Some examples of some of the other advantageous properties exhibited by the composite article may include exhibiting a Tg of> 150 ° C. and being able to release with a molding temperature of> 145 ° C. and a cure time of less than 3 minutes.

In a preferred embodiment, the glass transition temperature of the cured portion is, as exemplified by the following formula, when using the formulation of the present invention having the IMR agent and reaction inhibitor disclosed herein. Does not decrease by more than% (%): ΔTg = Tg, _{w / o IMR-} Tg, _{w / IMR} , in formula, Tg, _{w / o IMR} if IMR and reaction inhibitors are not present in the formulation. _{Tg, w / IMR} is the glass transition temperature of the formulation in which the IMR agent and the reaction inhibitor are not present in the formulation.

Composite articles, products, or moldings using the curable epoxy resin composite formulations of the present invention may be used in the following applications: molded automotive composites for closed panel structures such as hoods, trunks, lift gate structure supports. thing.

The following examples are presented to illustrate the invention in more detail, but should not be construed as limiting the scope of the claims. Unless otherwise indicated, all parts and percentages are by weight.

The various raw materials (ingredients or constituents) used in the following Examples (Inv. Ex.) And Comparative Examples (Comp. Ex.) Of the present invention are described in Table I below of the present specification.

Test Method Determination of Glass Transition Temperature (Tg) “DSC” is an abbreviation for dynamic differential scanning calorimetry.

"DSC glass transition temperature (Tg)" means the glass transition temperature of a particular material determined using DSC.

The Tg value of the final molded article was determined by the method described in DMA-ASTM D5418-15 (2015).

Determining the induction time The induction time can be determined using the TA Instruments Q2000 Differential Scanning Calorimetry (DSC). A 5 mg-12 mg compounded resin sample was placed in the bottom of a pre-weighed sealable DSC pan. Next, the DSC pan was sealed and crimped. The sample was run using the following method:
Step (1): Lamp 100 ° C / min to 150 ° C,
Step (2): Equilibrate at 150 ° C,
Step (3): Isothermal for 15 minutes, and Step (4): Stop execution.

The data obtained by running the sample in the above method can be plotted as a function of time using the TA Universal Analysis software, and two inflections are used using the inflections of the sample measured and plotted on the graph. The induction time can be determined by calculating the time between the inflections.

Determination of Curing Time and Molding Temperature The curing time and molding temperature can also be determined using the ATA Instruments Q2000 Differential Scanning Calorimetry (DSC). A 5 mg-12 mg compounded resin sample was placed in the bottom of a pre-weighed sealable DSC pan. Next, the DSC pan was sealed and crimped. The sample was run in the following way:
Step (1): Lamp to a predicted molding temperature of 100 ° C./min,
Step (2): Equilibrate at the predicted molding temperature ° C.,
Step (3): Isothermal for 15 minutes, and Step (4): Stop execution.

The data obtained by running the sample in the above method can be plotted as a function of time using TA Universal Analysis software. The molding temperature can be determined by the peak exotherm generated in less than 3 minutes.

Determining the release of a composite article The release of a suitable part from the forming mold is determined when the part is released from the mold tool at the end of the specified curing time without damaging the shape of the part. ..

Examples 1-8 and Comparative Examples A-H
General Procedures for Sample Preparation Samples of epoxy resin formulations were first prepared by heating 100 grams of resin (s) to 90 ° C. in a 20 Max Mixer Cup (manufactured by BlackTek Inc.). The amounts of IMR, Technology Nanodicy, and accelerators listed in Tables II and III were added to the resin while the resin was hot, and the resulting high temperature mixture was immediately added to the SpeedMixer ™ Lab Mixer System (FlashTek Inc.). I put it in (made). The mixture of components was mixed at 3,000 rpm (RPM) for 1 minute. The resulting sample mixture was then tested by DSC and other property measurements described above.

Partial molding A sample of the epoxy resin formulation prepared as described above was molded and cured according to the following general procedure.

The epoxy formulation was determined by adding a designated resin blend with a curing agent, accelerator, reaction inhibitor, and internal mold release agent to the mixing vessel. After sufficient mixing, the resin was heated to about 85 ° C. and the resin was drawn through a blade of a specified gap height to film the material into a resin sheet to produce a film of the desired thickness. Next, the film was cooled and rolled. The top layer of the film and the bottom layer of the film were placed on the prepreg line and unidirectional carbon fibers of 24K tow were pulled between the fop and the bottom film layer to create a film-fiber-film structure. The structure was exposed to heat up to 120 ° C. for 5 to 45 seconds while applying pressure by pulling the structure with a heating roller. This allows the resin film to penetrate the fiber bed and create a carbon fiber / epoxy prepreg. Cool the prepreg to room temperature and roll. Next, it is expected that the molding material will be cut from the prepreg to a predetermined volume and filled with the shape created in the mold cavity. The molding material is placed in a hot forming tool at a temperature in the range of 145 ° C to 160 ° C. The hot forming tool is closed with force from a compression molding machine capable of applying pressures in the range of 100 PSI to 5000 PSI. Heat and pressure transform the prepreg material into the shape of the part. At time intervals of 2 to 5 minutes, the molding tool opens and the shape of the fully cured portion can be removed from the mold by mechanical ejection of that portion.

The emission properties of the hardened portion presented in the examples were completed by molding a conventional "hat" section portion with a chrome surface plated stainless steel tool. The general design dimensions of the hat portion were 9 inches x 12 inches, with a 6.25 inch wide recess and a 2.75 inch deep side wall.

From the data in Table II, it is concluded that the formulation containing 4 parts of Licorub WE4 and 0 to 3 parts of Unitid350 (Example 3) works well for continuous processes when the molding temperature is between 150 ° C and 155 ° C. Can be attached. The formulation containing 3 parts of Licorub WE4 (Example 4) can function well using a continuous process. Further, as shown in Table II, at a temperature of 150 ° C to 160 ° C, as the molding temperature increases, the induction time of the formulation decreases.

From the data in Table III, for the batch process, only 4 parts of Licorub WE4 and 3 parts of Unitid350 (Example 5) or 2 parts of Unitid350 (Example 6) work well when the molding temperature is 150 ° C. Then we can conclude.

As mentioned above, controlling the induction time to> 15 seconds by isothermal curing allows the dyssy-cured epoxy to be released from the molding tool without the cured product sticking to the mold surface. For example, in a batch resin formulation blending / mixing process, if the IMR agent is present in the resin formulation, the batch process may extend the mixing time at a particular temperature (see Comparative Examples A and B). sea bream). A formulation containing no IMR additive is described in Comparative Example A. In a continuous resin formulation blending / mixing process, if a suitable IMR agent is present in the resin formulation, the continuous process can minimize the residence mixing time at a temperature of> 60 ° C. (Examples). See 1 and Example 2). Formulations with blends / combinations of IMR agents and reaction inhibitors can provide the required induction time during the curing process, whether the process is a batch process or a continuous resin blending process (Example 1). 8 and Comparative Examples A to H).

In the examples, samples were run in batch and continuous methods and then tested for the properties shown in Table II and Table III. Induction time data, which is an analysis of heat flow (W / g) as a function of time (minutes) obtained from various examples, is available as TA Universal Analysis software and isothermal DSC scans, as is known in the art. Obtained using.

Claims (15)

(A) at least one epoxy resin compound, (b) at least one curing agent, (c) at least one curing accelerator, (d) at least one internal mold release agent, and (e) at least one. A curable epoxy resin composition comprising, and a reaction inhibitor. The epoxy composite composition is cured at a molding curing temperature and the epoxy composition is cured to at least 85% or more in a curing period of 3 minutes or less, and then released from the forming mold to obtain the obtained cured composite. The composition according to claim 1, wherein the composition has a Tg of more than 150 ° C. The composition according to claim 2, wherein the epoxy resin composition is released from the forming mold with an induction time of 15 to 60 seconds. The at least one epoxy resin compound is at least one diglycidyl ether of polyhydric phenol, at least one polyglycidyl ether of phenol-formaldehyde novolak resin, at least one oxazolidone group-containing polyglycidyl ether of phenol compound, and mixtures thereof. The composition according to claim 1, which is selected from the group consisting of. (I) The at least one epoxy resin compound is a diglycidyl ether of bisphenol A, (ii) the at least one curing agent is dicyandiamide, and (iii) the at least one curing accelerator is toluenebis-dimethylurea. p-chlorophenyl-N, N-dimethylurea, 3-phenyl-1,1-dimethylurea, 3,4-dichlorophenyl-N, N-dimethylurea, N- (3-chloro-4-methylphenyl) -N' , N'-dimethylurea, and urea compounds selected from one or more of their mixtures, (iv) said at least one internal demolding agent is an ester of montanic acid and a polyol, (v). ) The composition according to claim 1, wherein the at least one reaction inhibitor is a hydrocarbon having a carbon atom exceeding C18 and an acid functional group. The composition according to claim 5, wherein the acid functional group comprises a carboxylic acid or a derivative of a carboxylic acid, a sulfonic acid or a derivative of a sulfonic acid, a maleic anhydride or a derivative of maleic anhydride, and a mixture thereof. Add one or more of diluents, strengtheners, rubbers, plasticizers, bulking agents, colorants, flame retardants, smoke suppressants, thixotropy agents, adhesion promoters, biocides, antioxidants, and fillers. The composition according to claim 1. The filler was subdivided to fill the gaps between the curable epoxy resin composite composition and the fibers on or near the surface of the cured composite to provide a smoother surface for the cured composite. The composition according to claim 7, which comprises a solid. The composition of claim 8, wherein the finely divided solid filler comprises calcium carbonate, fumed silica, carbon nanotubes, and a mixture thereof. A method for producing a curable epoxy resin composition, which is a method for producing a curable epoxy resin composition.
(A) at least one epoxy resin compound, (b) at least one curing agent, (c) at least one curing accelerator, (d) at least one internal mold release agent, and (e) at least one. A method comprising mixing with a reaction inhibitor. A curable epoxy-based resin composite composition comprising (A) the curable epoxy composition according to claim 1 and (B) at least one structural material. The composite composition according to claim 11, wherein the structural material is a fiber material selected from the group consisting of carbon fiber, glass fiber, and a mixture thereof. A method for producing a curable epoxy-based resin composite composition, comprising mixing (A) the epoxy composition according to claim 1 with (B) at least one structural material. Method. (I) A composite article comprising the reaction product of the epoxy composition according to claim 1 and (ii) at least one structural material. A method for producing composite articles,
(I) (a) at least one epoxy resin compound, (b) at least one curing agent, (c) at least one curing accelerator, (d) at least one internal mold release agent, and (e). A step of mixing with at least one reaction inhibitor to form an epoxy composite formulation.
(II) A step of adding at least one structural material to the epoxy composite formulation of step (I) to form a combination of the epoxy and the structural material composite composition.
(III) A method comprising the step (II) of curing the combination of the epoxy and the structural material composite composition in step (II) by isothermal molding at a temperature above 145 ° C.

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